Disk prosthesis



FIG. 1 is a perspective view of a disc prosthesis showing my new design;

FIG. 2 is a left side elevation thereof;

FIG. 3 is a right side elevation thereof;

FIG. 4 is a bottom plan thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a rear elevation thereof; and,

FIG. 7 is a front elevation thereof. 

The ornamental design for a disk prosthesis, as shown and described. 